1. Field of the Invention
This invention relates to pads for the support of heavy equipment such as air conditioners, heaters and transformers.
2. Discussion of Related Art
The high cost of poured onsite concrete bases for various types of air conditioning, heating and electrical equipment has given rise to a growing market of precast concrete bases. Although such precast bases are usually less expensive than site poured bases, they are generally very heavy requiring heavy equipment or several laborers to set into place. Precast concrete bases are also expensive to ship and thus lose their cost advantage when transported to points at much greater distances than those within the local area.
Certain substitutes for precast concrete bases have been suggested. For instance, U.S. Pat. No. 4,050,659, issued Sept. 27, 1977, shows a transformer pad having a fiberglass reinforced plastic exterior surface and an expanded foam core. U.S. Pat. No. 4,023,755 issued May 17, 1977 to Alesi, Jr., shows a transformer mounting pad wherein structural support for the load is provided by a wood and foam core enclosed within a plastic shell, U.S. Pat. No. 3,772,845, issued May 27, 1973 to Unger, shows a ground mounting base for use with heat exchanger units. The base comprises a pad of concrete employing vermiculite as its primary aggregate, a wire screen reinforcement, and a top layer of sand aggregate concrete. U.S. Pat. No. 3,713,620, issued Jan. 30, 1973 to Tkach, shows a machine supporting slab formed of a rigid body of closed-cell foam resin material of high density covered by a metal sheath spanning the top and extending around the marginal edges of the body.